Instrument panel for a motor vehicle having an airbag device integrated in a ventilation arrangement

ABSTRACT

An airbag module and instrument panel assembly for a motor vehicle having at least one ventilation outlet and a ventilation duct attached thereto and arranged behind an instrument panel. The airbag module is fastened behind the instrument patent and has a gas generator and a folded airbag arranged within its housing wherein a ventilation outlet is closed by a grid that opens when the airbag module is triggered and is provided within the instrument panel for the unfolding airbag. The airbag module is arranged adjacent to the ventilation duct in such a manner that when the airbag module is triggered, the airbag unfolds into the ventilation duct and from there unfolds out of the instrument panel through the ventilation outlet. The pressure of the unfolding airbag moves away from the ventilation outlet which is arranged within the instrument panel.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to PCT/EP2003/012613, filed Nov. 12,2003 and GB 10253185.4, filed Nov. 15, 2002.

FIELD OF THE INVENTION

This invention relates to an instrument panel for a motor vehiclecomprising of at least one ventilation outlet and a ventilation ductattached thereto and arranged behind the instrument panel, and furtherhaving an airbag module which is fastened behind the instrument paneland has a gas generator and a folded airbag arranged within its housing.An outlet opening, which is closed by a covering that opens when theairbag module is triggered, is provided within the instrument panel forthe unfolding airbag.

BACKGROUND OF THE INVENTION

An instrument panel of the type related to this invention is known fromU.S. Pat. No. 6,264,233. To the extent that an airbag module and aventilation duct are arranged behind the instrument panel of a vehicle,there is provided a covering that covers both components and on the onehand forms the covering for the airbag module and on the other hand hasintegrated within itself a ventilation outlet having a ventilation covercovering the outlet the ventilation cover of that design being attachedto the ventilation duct when the cover or ventilation outletrespectively is still in the position established within the instrumentpanel. The unfolding airbag forces the covering open when the airbagmodule is triggered, and the ventilation outlet also releases itselffrom the ventilation duct fastened to the instrument panel.

The known instrument panel and the fitting arrangement of ventilationduct and airbag module of the type described above has the disadvantagethat a correspondingly large space is required for accommodating anairbag module behind the instrument panel and that the common coveringfor the ventilation duct and airbag module features substantialdimensions, this covering to be opened when a trigger occurs.

In view of the foregoing it is an object of the invention to reduce thespace requirement for the fitting arrangement of the airbag modulebehind the instrument panel in an instrument panel.

This object, including advantageous embodiments and further developmentsof the invention, is accomplished by the content of the claims thatfollow this description.

SUMMARY OF THE INVENTION

The basic concept of the invention provides an airbag module arrangedadjacent to the ventilation duct in such a manner that, when the airbagmodule is triggered, the airbag unfolds into the ventilation duct andfrom there unfolds out of the instrument panel through the ventilationoutlet, the pressure of the unfolding airbag moving away the ventilationoutlet arranged within the instrument panel. The invention has theadvantage that the opening in the instrument panel, which is necessaryfor providing ventilation is also used for the escape of the airbag fromthe airbag module, so that it is possible to dispense with an extraopenable covering provided in the instrument panel for the escape of theairbag. Since the ventilation duct is simultaneously used as an escapechannel for the airbag when the airbag unfolds, a much more space-savingpackaging arrangement of the airbag module behind the instrument panelis possible.

In one exemplary embodiment of the invention, housing wall of the airbagmodule is adjacent to the ventilation duct and forms a dividing wall forthe duct and, when the airbag module is triggered, moves into the ductin such a manner that there is formed an escape channel leading from theairbag module to the ventilation outlet. In this exemplary embodiment,there remains open, within the wall enclosing the ventilation duct, asubregion that is closed by the assigned housing wall of the airbagmodule when the airbag module is installed.

An alternative form of the invention may be provided that the dividingwall of the ventilation duct adjacent to the airbag module forms ahousing wall for the airbag module and that, when the airbag module istriggered, the common dividing wall and housing wall moves into theventilation duct in such a manner that there is formed an escape channelleading from the airbag module to the ventilation outlet. In thisembodiment, the common dividing and housing wall is assigned to theventilation duct, so that it is possible to dispense with an additionalwall on the housing of the airbag. This has the advantage that therequired motion of the common dividing and housing wall into theventilation duct may already be taken into consideration during thedesign and manufacture of the ventilation duct.

In one exemplary embodiment of the invention, it is provided that theairbag module is arranged laterally next to the ventilation duct and thedividing and housing wall swings into the ventilation duct around afixed point located far from the instrument panel. In regard to thefitting arrangement of dividing and housing wall, it may here beprovided that the ventilation outlet partially overlaps the airbagmodule and that region of the dividing and housing wall that faces theinstrument panel forms a diagonal kink leading to that edge of theventilation outlet located on the module side, the mutual dividing andhousing wall running behind the ventilation outlet may be furtherprovided that the kink is dimensioned in such a manner that the kinkfits into place on the opposite edge of the ventilation outlet duringthe swinging of the dividing and housing wall, thus forming the escapechannel for the unfolding airbag.

In an alternative embodiment, the invention provides that the airbagmodule is arranged on the side of the ventilation duct opposite theinstrument panel.

To reduce the overall depth of the fitting arrangement of ventilationduct and airbag module behind the instrument panel according to thisinvention in it may be provided that the airbag module is designedL-shaped with one section located laterally next to the ventilation ductand one section located the ventilation duct opposite the instrumentpanel, the common dividing and housing walls of the ventilation ductadjacent to the airbag module being integrally joined together andswinging into the ventilation duct when the airbag module is deployed.

Since a separate direct opening in the instrument panel is not requiredas an escape hole for the airbag, measures are provided in one exemplaryembodiment of the invention to ensure that the airbag reliably unfoldsout of the airbag module through the ventilation duct. For this purpose,it is provided that a partition wall arranged within the housing of theairbag module divides the airbag, which is folded into the housing, intotwo folding packages, one folding package being arranged adjacent to theventilation outlet. In this case it may be advantageous for the foldingpackage adjacent to the ventilation outlet to have a smaller dimensionthan the second folding package and act as a starting bubble for pullingout the second folding package when the airbag module is triggered.Depending on the structural factors, the invention also includes theconcept that the fitting arrangement of a plurality of partition wallsdivides the folded airbag into a plurality of folding packages.

In regard to installing an airbag module onto the ventilation duct, itmay be provided that a holding device attaches the airbag module to theventilation duct and fastens it to the interior of the instrument panel.

In one exemplary embodiment of the invention, it is provided that acover covers and holds the airbag in the vicinity where the airbagmodule is connected to the mutual dividing and housing wall, the airbagbeing folded into the housing and the foil tearing open when the airbagunfolds and protection between the airbag and the edges of theventilation outlet.

Since a very narrowly designed ventilation outlet may cause problems inregard to the speed at which the airbag unfolds, it is provided in oneexemplary embodiment of the invention that predetermined breaking linesseparate the vicinity of the instrument panel adjacent to theventilation outlet from the rest of the instrument panel so that theunfolding airbag separates, from the instrument panel, both theseparated region and the ventilation outlet combining to act as escapehole for the airbag. In this case, the specified area of the instrumentpanel advantageously enlarges the escape hole for the airbagappropriately.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing depicts exemplary embodiments of the invention, which willbe described below. The drawing shows:

FIG. 1 is a longitudinal section of a subregion of an instrument panelhaving ventilation arrangement and airbag device according to a firstembodiment of this invention prior to triggering of the airbag device,

FIG. 2 shows the airbag device shown in FIG. 1 in a first stage ofunfolding of the airbag during deployment of the airbag device,

FIG. 3 shows the airbag device shown in FIG. 1 in an advanced stage ofunfolding of the airbag during deployment of the airbag device,

FIG. 4 is a cross-sectional view of a second embodiment of the airbagdevice of this invention,

FIG. 5 shows the airbag device of FIG. 4 in a stage of partial unfoldingof the airbag during deployment,

FIG. 6 shows an airbag arrangement in accordance with a third embodimentof this invention,

FIG. 7 shows an airbag arrangement in accordance with a fourthembodiment of this invention,

FIGS. 8 a-c shows different stages of installation of the airbag devicein accordance with this invention on the ventilation duct and instrumentpanel.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 depicts an instrument panel 11 contiguous to a windshield 10 of amotor vehicle in which an opening for both the ventilation outlet andescape of the airbag is arranged directed upwardly toward the windshield10, so that in this fitting arrangement of the instrument panel, boththe ventilation duct and airbag module are underneath the instrumentpanel 11 relative to the windshield.

In particular, there is provided within the instrument panel aventilation outlet 13, which is covered by a ventilation grill 14, whichfits into the instrument panel 11 with positive fit. A ventilation duct12, which is enclosed by walls 15 and for example spreads the air supplyacross the width of the vehicle underneath the instrument panel 11, isarranged underneath the ventilation outlet 13, the air supply beingconveyed into the passenger compartment if necessary by a plurality ofventilation outlets 13 configured in the instrument panel 11.

As still to be described in detail, an airbag module 16, within whosehousing 17 a gas generator 19 and a folded airbag 18 are arranged, ispositioned underneath the instrument panel 11 and directly adjacent to aventilation duct 12. A partition wall 20 arranged in the housing 17 ofthe airbag module 16 divides the folded airbag 18 into two folded, andspecifically into one folded package 21 directly adjacent to theventilation outlet 13 and one folded package 22 arranged on the oppositeside of the partition wall 20.

To the extent that the ventilation duct 12 and airbag module 16 contactone another because of their directly adjacent arrangement, there isprovided a mutual dividing and housing wall 23 which, as cooperatingwith walls 15 and defining the ventilation duct 12. The wall 23 isconnected one of walls 15 of the ventilation duct 12 at a hingeconnection 24 in such a manner that the pressure of the unfolding airbag18 swings the dividing and housing wall 23 into the ventilation duct 12when the airbag module 16 is triggered.

In this case the dividing and housing wall 23 is arranged relative tothe ventilation outlet 13 in such a manner that the ventilation outlet13 overlaps the mutual dividing and housing wall 23, wherein the regionof this wall that faces the instrument panel 11 and is contiguous withthe instrument panel 11 forms a diagonal kink 25 leading to the edge ofthe ventilation outlet 13 running on the side of the airbag module 16,the dividing and housing wall 23 running behind the ventilation outlet13. This kink 25 is dimensioned in such a manner, that the edge of wall23 fits into place on the opposite edge 26 of the ventilation outlet 13when the mutual dividing and housing wall 23 swings into the ventilationduct 12, thus forming and delimiting an escape channel 40 for theunfolding airbag 18.

To the extent that the ventilation outlet 13 is closed by a ventilationgrill 14, a rebound strap 28 holds the ventilation grill on theinstrument panel 11 so that the ventilation grill 14 will not fly aroundthe passenger compartment when instrument panel 11 releases theventilation grill 14. The region of the ventilation grill 14 facing theairbag module 16 also includes an air baffle 27 extending behind theinstrument panel 11 to the ventilation facing 14 to open forcefully.

FIGS. 1 to 3 depict the triggering of the airbag module 16 in detail,FIG. 2 showing that the gas released by the gas generator 19 when thegas generator is ignited first pressurizes the first folded package 21facing the instrument panel 11, so that this folding package exerts acorresponding pressure on the dividing and housing wall 23 toward theventilation duct 12. This pressure presses the dividing and housing wall23 around the hinge connection 24 inwards into the ventilation duct 12.At the same time, the folded package 21, which unfolds next, exerts acorresponding upwardly-directed pressure on the ventilation grill 14because of the air baffle 27 located on the underside of the ventilationgrill 14, forces the ventilation grill 14 to swing open in the directionof the windshield 10 and releases the ventilation outlet 13 as anunfolding hole for the airbag 18. In this respect, after the ignition ofthe gas generator 19, the first folding package 21 first acts as anextraction bubble that then pulls the second folding package 22 arrangedunderneath the partition wall 20 out of the housing 17 of the airbagmodule 16 during the further gas pressurization.

In the case of very narrow ventilation outlet 13 and grill 14, it may beprovided that predetermined breaking lines separate, from the rest ofthe instrument panel 11, in that region of the instrument panel 11adjacent to the respective ventilation outlet 13 and preferablysurrounding the ventilation outlet 13. In such a configuration, when theairbag module 16 unfolds, the unfolding airbag detaches both the regionof the instrument panel 11 separated by predetermined breaking lines andthe ventilation outlet 13 from the instrument panel 11 so that anappropriately larger escape hole is formed for the airbag 18.

The exemplary embodiment that is depicted in FIG. 4 and whose triggeringis depicted in FIG. 5 differs from the exemplary embodiment previouslydescribed in FIGS. 1 to 3 in that the airbag module 16 is configuredL-shaped, having one section 30 located laterally next to ventilationduct 12 and one section 29 located behind the ventilation duct 12opposite instrument panel 11, so that the airbag module 16 wrapspartially around the ventilation duct 12. This provides a particularlyspace-saving fitting arrangement of ventilation duct 12 and airbagmodule 16. In this design of airbag module 16, two wall sections ofventilation duct 12 each form adjacent mutual dividing and housing walls23 which are integrally joined together and again swing into theventilation duct 12 around a hinge-like connection 24 when the airbagmodule is triggered. Because the fitting arrangement of partition wall20, which is again provided, is matched to the shape of airbag module16, the design takes care that the first folding package 21, which thegas generator 19 first pressurizes, acts as extraction bubble for thesecond unfolding package 22, as described in FIGS. 1 to 3.

FIGS. 6 and 7 depict exemplary embodiments of the invention in which thepartition wall 20 or plurality of partition walls 20, respectively,provided in housing 17 of airbag module 16 form corresponding first,second or further airbag folded packages in order to assure that theairbag 18 smoothly unfolds out of the airbag module 16 and ventilationduct 12, respectively, depending on the assignment of the airbag module16 to the ventilation duct 12.

Finally, FIGS. 8 a-c show that simplified installation can be associatedwith the design of an instrument panel having the ventilationarrangement and airbag device according to invention. Here theventilation duct 12 and its assigned walls 15 and 23 are fastened to theinstrument panel 11. In this case the ventilation duct 12 is providedwith a mounting plate 32, which is arranged to accommodate the airbagmodule 16 and has an opening 33 built therein, wherein a projecting part34 configured on the airbag module 16 is used to insert the airbagmodule into the opening 30 of the mounting plate 32 and, after theairbag module has been swung toward the mutual dividing and housing wall23, it is fastened to the instrument panel 11 using a fastener 35. Forthis installation procedure, the airbag module 16 is provided with acover layer 31 for the folded airbag 18 when it fits into place on thedividing and housing wall 23, which is common with the ventilation duct12, this cover layer preferably being made of a welded-on foil thattears open from the pressure of the unfolding airbag. As evident fromFIG. 3, the cover 31 may be configured in such a manner that it lies asprotection between the airbag 18 and the edges of the ventilation outletin particular when the airbag 18 unfolds, so that the fabric of theairbag 18 is treated gently and there is a reduced danger that thefabric will tear.

The characteristics of the object of these documents disclosed in theabove description, the claims, the abstract and the drawing may beessential for the realization of the invention in its variousembodiments both individually and in any desired combination with eachother.

1. An airbag module and instrument panel assembly for a motor vehiclehaving at least one ventilation outlet and a ventilation duct attachedthereto and arranged behind an instrument panel, and an airbag modulewhich is fastened behind the instrument panel and having a gas generatorand a folded airbag arranged within a housing, the airbag housing havingwithin it a partition wall arranged to divide the airbag into a firstand a second package, the first folding package being arranged adjacentto the ventilation outlet which is closed by a grill, the assemblycomprising the airbag module being arranged adjacent to the ventilationduct in such a manner that, when the airbag module is triggered, theairbag unfolds into the ventilation duct and from there unfolds out ofthe instrument panel through the ventilation outlet opening, thepressure of the unfolding airbag moving away the grill arranged withinthe instrument panel.
 2. An airbag module and instrument panel assemblyaccording to claim 1, wherein predetermined breaking lines separate asegment of the instrument panel adjacent to the ventilation outlet fromthe remainder of the instrument panel so that the unfolding airbagseparates the segments from the remainder of the instrument panel, andboth the separated segment and the ventilation outlet form an escapehole for the airbag.
 3. An airbag module and instrument panel assemblyaccording to claim 1, wherein the partition wall divides the foldedairbag into the first and second folding packages.
 4. An airbag moduleand instrument panel assembly according to claim 1, wherein a housingwall of the airbag module adjacent to the ventilation duct forms adividing wall for the ventilation duct and, when the airbag module istriggered, the dividing wall moves into the ventilation duct in such amanner that there is formed an escape channel leading from the airbagmodule to the ventilation outlet.
 5. An airbag module and instrumentpanel assembly according to claim 1, wherein a dividing wall of theventilation duct is adjacent to the airbag module and forms a housingwall for the airbag module and when the airbag module is triggered, thedividing wall moves into the ventilation duct in such a manner thatthere is formed an escape channel leading from the airbag module to theventilation outlet.
 6. An airbag module and instrument panel assemblyaccording to claim 1, wherein the airbag module is arranged laterallynext to the ventilation duct and a dividing and housing wall, locatedadjacent to the airbag module and forming a housing wall for the airbagmodule, swings into the ventilation duct around a fixed point.
 7. Anairbag module and instrument panel assembly according to claim 1,wherein the airbag module is arranged on a side of the ventilation ductopposite the instrument panel.
 8. An airbag module and instrument panelassembly according to claim 7, wherein the airbag module is designedL-shaped with a first section located laterally next to the ventilationduct and a second section located on the side of the ventilation ductopposite the instrument panel, and further wherein a dividing wall,located adjacent to the airbag module and forming a housing wall for theairbag module, is integrally joined together over the first and secondsections, and swings into the ventilation duct when the airbag module istriggered.
 9. An airbag module and instrument panel assembly accordingto claim 1, wherein the first folding package adjacent to theventilation outlet has a smaller dimension than the second foldingpackage and acts as a starting bubble for the pulling out of the secondfolding package when the airbag module is triggered.
 10. An airbagmodule and instrument panel assembly for a motor vehicle having at leastone ventilation outlet and a ventilation duct attached thereto andarranged behind an instrument panel, and an airbag module which isfastened behind the instrument panel and having a gas generator and afolded airbag and further having a ventilation outlet opening which isclosed by a grill, the assembly further having a dividing wall of theventilation duct adjacent to the airbag module and forming a housingwall for the airbag module, and further wherein the ventilation outletpartially overlaps the airbag module, and further wherein a region ofthe dividing wall that faces the instrument panel forms a diagonal kinkleading to an edge of the ventilation outlet located adjacent themodule, and wherein the dividing and housing wall runs behind theventilation outlet, the assembly comprising the airbag module beingarranged adjacent to the ventilation duct in such a manner that, whenthe airbag module is triggered, the dividing wall moves into theventilation duct in such a manner that there is formed an escape channelleading from the airbag module to the ventilation outlet, such that theairbag unfolds into the ventilation duct and from there unfolds out ofthe instrument panel through the ventilation outlet opening, thepressure of the unfolding airbag moving away the grill arranged withinthe instrument panel.
 11. An airbag module and instrument panel assemblyaccording to claim 10, wherein the kink is dimensioned such that thekink fits into place on an opposite edge of the ventilation outletduring the swinging of the dividing wall, thus forming and delimitingthe escape channel for the unfolding airbag.
 12. An airbag module andinstrument panel assembly for a motor vehicle having at least oneventilation outlet and a ventilation duct attached thereto and arrangedbehind an instrument panel, and an airbag module which is fastenedbehind the instrument panel and having a gas generator and a foldedairbag and further having a ventilation outlet opening which is closedby a grill, the assembly comprising the airbag module being attached tothe ventilation duct by means of a holding device which fastens theairbag module to the interior of the instrument panel in such a mannerthat, when the airbag module is triggered, the airbag unfolds itselfinto the ventilation duct and from there unfolds out of the instrumentpanel through the ventilation outlet opening, the pressure of theunfolding airbag moving away the grill arranged within the instrumentpanel.
 13. An airbag module and instrument panel assembly for a motorvehicle having at least one ventilation outlet and a ventilation ductattached thereto and arranged behind an instrument panel, and an airbagmodule which is fastened behind the instrument panel and having a gasgenerator and a folded airbag and further having a ventilation outletopening which is closed by a grill, and further having a cover coveringand holding the airbag in the vicinity where the airbag module isconnected to a dividing wall of the ventilation duct, the dividing walllocated adjacent to the airbag module and forming a housing wall for theairbag module, the airbag being folded into the housing, the assemblycomprising the airbag being arranged adjacent to the ventilation duct insuch a manner that, when the airbag module is triggered, the coveropening when the airbag unfolds and lying down as protection between theairbag and edges of the ventilation outlet, and the airbag unfoldinginto the ventilation duct and from there unfolding out of the instrumentpanel through the ventilation outlet opening, the pressure of theunfolding airbag moving away the grill arranged within the instrumentpanel.